The boss of a Shanghai-based property developer lost more than a billion dollars Monday, as fears over the potential collapse of Chinese real estate giant Evergrande sent panic across Hong Kong trading floors. Zhang Yuanlin, chairman of Sinic Holdings Group, saw his net worth drop from $1.3 billion Monday morning to $250.7 million by the afternoon, according to Forbes, when his firm was forced to halt trading in Hong Kong following an 87 per cent slump in its share price.